Core bit



Dec. 29, 1942.

CORE BIT Filed June 15, 1940 w. B. NOBLE ETAL} 3 Sheeos-Sheet 1 Wiley 5. IVOHe. 50/14: 55 10::-

INVENTOI Q.

3 Sheets-Sheet 5 mvENTog 25L 12 &2

W. B. NOBLE ETAL CORE BIT Filed June 15, 1940 mm lllllll Dec. 29, 1942.

mama Dec. 29, 1942 CORE BIT Wiley B. Noble, Houston, Ten, and John F. Shaw, Los Angeles, Calif., asslgnors to Reed Roller Bit Company, Houston, Ten, a corporation of Texas Application June15, 1940, Serial No. 340,698

7 Claims.

This invention relates to a core bit and particularly to that type of core bit adapted to receive a core barrel which may be dropped into the bit from the surface of the ground and removed from the bit by means of a wire line through the drill stem.

The general object of this invention is to provide a core bit of the type referred to which will be easily and cheaply constructed and more durable in use than those heretofore employed.

A further object of this invention is to provide a coring bit employing roller cutters in which the bearings for such cutters are carried by integral parts of the bit shank.

Another object of this invention is to provide a bit of the character referred to in which there will be no constricted portion in the passageway through the bit above the cutters.

Another object of this invention is to provide a bit of the type referred to in which the cutters will be mounted by means of relatively small and inexpensiveand easily accessible weld connections.

Anotherobject of this invention is to provide a bit of the type'referred to in which the bearings for the cutters will be supported directly by integral parts of the shank of the bit and will transmit the forces from the cutters and cutter bearings directly to the bit shank.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are shown by way of example and illustration three embodiments of this invention.

In the drawings:

Fig. 1 is a longitudinal cross section through a bit constructed in accordance with this invention.

Fig. 2 is a similar view showing a section through the lower part of the same bit taken at right angles to Fig. 1 and showing a drill collar carried on the upper end of the bit.

Fig. 3 is a partial side elevation of the shank of the bit constructed in accordance with this invention without the cutters and cutter bear ings in place therein.

Fig. 4 is a view similar to but taken at right angles to Fig. 3.

Fig. 5 is a transverse section taken along the line 5-5 of Fig. 1.

Fig. 6 is a bottom plan view of the bridge employed in this invention;

Fig. 7 is a fragmentary view similar to the left hand portion of Fig. l but showing'a modified form of outside cutter bearing construction.

Fig. 8 is a view similar to Fig. 7 but showing a still further modified form of bearing construction.

that the bit shank constructed in accordance with this invention is preferably made in a plurality of segmental parts, these in the illustration given being four in number. Two of these segmental parts designated I are adapted to support the inside cutter bearings in a manner presently to be described and the other two designated by the numeral 2 are adapted to support the bearings for the outside cutters. These segmental parts are welded together along their adjacent edges as shown at 3, the respective parts being. beveled adjacent their outer surfaces to form V-shaped weld grooves as illustrated.

The inside cutterbearings are carried on the bridge 4 illustrated in Fig. 6, these bearings each ments I and by a short bearing spindle I0 one end of which extends into the opening .II in the segment I and the other end of which extends into openings I2 in the bridge 4. The respective ends of this spindle I 0 are welded into said openings II and I2 as shown at I3 and I4.

As illustrated in Figs. 1 and 2 the outside cutters l5 and the inside cutters I6 are mounted on their respective bearings by means of suitable balls and rollers. The outside cutters I5 in Fig. 1 have two sets of radial roller bearings I l and I8 and a single row of balls I9 for carrying the end thrust. In the assembling of the cutters IS on their spindles ID, the spindles will first be placed within the cutters and the balls I4 wi l be dropped in through the passage 20. The plug 2| will then be slipped into place in this passage to prevent the balls from dropping out and the rollers I I will be put in place on the annular flange 9 of the segment 2. Cutter I5 with the spindle in place will then be slipped over the rollers "II with the spindle entering the. opening II thus holding-the plug 2| in place. The inner rollers I8 may then be put in place and the opening I2 in the bridge engaged with the spindle to hold the inner rollers in position.

The inside cutters I6 are assembled on their .Referring first to Figs. 3 and 4, it will be seen With all of the parts assembled in the manner indicated the segments are then welded together 'as shown at 3. Thereafter the completed shank is threaded as shown at 26. The finished product may now be screwed into the drill collar 21.

After the bit has been completed by the welding at 3, 8, l3 and I4 the opening through the shank of the assembled bit is bored or machined to form a smooth inner surface for the reception of a seating ring 28. This seating ring forms a seat for the core barrel later to be used in con nection with the bit and is provided with longitudinal channels in its outer surface as shown at 29 which serve as slush passageways. The seating ring 28 is preferably made in the form of an integral casting with the channels 29 cast therein, the outer surfaces of the lands between the channels 29 preferably being machined so as to form a good fit with the inner surface of the opening through the shank of the bit, and the beveled upper end surface 30 of this ring will likewise be machined to form a seat for the reception of the core barrel or center bit as the be in axial alignment with the bored zone 3| of the ring 28 and with the threads on the shank of the bit in order that the core barrel may be properly received and held during the coring op eration. a

It will be noted that the bearings for each of the cutters, both inside and outside, are in the structure just described carried by the legs on the respective shanks I and 2 so that all forces transmitted from these cutters will be transmitted through their bearings directly to these legs which form integral parts of the shank on the completed bit. Due to this direct transmission of forces from the cutters to the shank of the bit the likelihood of failure of any of the various parts 'in service is greatly reduced.

It will further be seen that a bit has been provided in which the various parts may be easily and cheaply constructed and assembled with a minimum of labor to provide a completed bit of great strength and durability.

It will further be apparent that in the construction described the passageway 24 through the bridge does not provide any constriction which would tend to clog up and interfere with the action of or removal of the core barrel or center bit. Any cuttings from the formations entering the passageway 24 through the bridge may readily pass through this opening and out into the space above the cutters and thence be washed away by the slush.

Referring now to Fig. 7 of the drawings, there is illustrated a slightly modified form of outside cutter bearing. In this form, the thrust bearing for the outside cutter is an integral part of the bridge, whereas the radial bearing as in the form shown in Fig. 1' is an integral part of the shank of the bit. In this form the segment 2 is of the same form as in that shown in Fig. 1. The bridge, however, instead of being provided with .the openings I2 is provided with projecting bearing parts each having a ball race 32 and a pin 33 which projects into the opening II in the segment I.- This pin is then welded in place as shown at 34. In the course of assembling the outside cutters shown in Fig. 7, one of these cutters shown at 35 is slipped over the thrust bearing carried by the bridge and the balls 36 which serve to take the thrust from the cutter 35 are dropped into place through a vertical passageway 31 in the bridge. This passageway is then plugged and the plug welded in place in the manner heretofore described. The rollers 38 will then beplaced about the annular flange 9 on the segment I and the cutter together with the bearing on the bridge will be assembled with respect to the segment I and welded into place.

In the form shown in Fig. 8, the same bridge as is employed in connection with Fig. 1 is used but the segment 39 is formed with an integral spindle which provides the entire bearing for the outside cutter 35. On this spindle is a roller race 40 for receiving the rollers 4| and a ball race 42 for receiving the balls 43. In assembling this device the rollers 4| are first placed on the bearing spindle in their race 40 and the cutter 35 is then placed over this spindle and the rollers 4|. The balls 43 are then inserted through a suitable passageway 44 in the integral spindle and then this passageway is plugged. After this the end of the integral bearing spindle is inserted into the opening l2 in the bridge and welded in place therein.

We claim:

1. A core drill comprising a shank, integral lugs extending downwardly from said shank on opposite sides thereof and each having an integral downwardly and inwardly extending bearing spindle thereon, a roller cutter on each of said spindles, and an annular bridge engaging the inner ends of said spindles and spaced downwardly from the main body of said shank and having a passageway therethrough adapted to receive a core.

2. A core drill comprising a shank, integral lugs extending downwardly from said shank on opposite sides thereof and each having an integral downwardly and inwardly extending bearing spindle thereon, a roller cutter on each of said spindles and an annular bridge engaging the inner ends of said spindles and spaced downwardly from the main body of said shank and having a passageway therethrough adapted to receive a core, said bridge having openings therein for receiving the ends of said spindles and the ends of said spindles being secured in said openings.

3. A core drill comprising a shank, integral lugs extending downwardly from said shank on opposite sides thereof and each having a downwardly and inwardly extending annular flange providing a bearing race and an opening within said bearing race, a roller cutter surrounding said annular flange and an annular bridge having viding additional bearing races within said cutters and engaging said openings within said flanges.

5. A core drill comprising a shank, integral .lugs extending downwardly from said shank on opposite sides thereof and each having a downwardly and inwardly extending bearing spindle thereon, said bearing spindles being in the form of annular flanges having openings centrally thereof, an annular bridge disposed centrally of the drill intermediate said flanges and having .separate parts secured thereto and engaging within the openings in said annular flanges and providing additional bearing races, a roller cutter surrounding each 01' said flanges and the bearing portions of said parts and means for securing said parts to said bridge and to said flanges.

6. A core drill comprising a shank, integral lugs extending downwardly from said shank on opposite sides thereof and each having a downwardly and inwardly'extending bearing spindle thereon, a roller cutter on each of said spindles, and an annular bridge engaging the inner ends of said spindles and having a passageway therethrough adapted to receive a core, each of said spindles including a ball race and a corresponding ball race within each 0! said cutters, and a passageway extending transversely of said spindle and substantially longitudinally otthe drill for the insertion of balls into said ball race. 1

7. A core drill comprising a shank, integral lugs extending downwardly from said shank on opposite sides thereof and each having a downwardly and'inwardly extending bearing spindle thereon, a roller cutter on eachiof said spindles and an annular bridge having inside cutter spindles formed integrally with it and extending downwardly and outwardly, each of said last mentioned cutter spindles having ball races thereon, and said bridge having passageways from the interior of its central opening and extending to said ball races whereby balls may be introduced into said races through said passageways.

WILEY B. NOBLE. JOHN F. SHAW. 

